1. Field
The present invention relates to a dish washing machine, and more particularly, to a dish washing machine that is capable of preventing the excessive increase of wash water pressure in a sump due to an accumulation of foreign matter in the sump.
2. Description of the Related Art
A dish washing machine is a machine that automatically washes dishes using cold water or hot water. A conventional dish washing machine includes a machine body, a washing tub formed in the machine body, dish baskets mounted in the washing tub, and injection nozzles mounted at an upper part, a middle part, and a lower part of the washing tub to inject wash water, which is disclosed in Korean Patent Application Publication No. 2006-24597.
At a bottom of the washing tub is mounted a sump to receive wash water and pump the wash water to the respective nozzles. The sump includes a sump housing forming an external appearance of the sump, a lower casing coupled to a top of the sump housing and having a filth chamber, and an upper casing coupled to a top of the lower casing and having a flow channel to guide the wash water to the upper and lower parts of the washing tub.
The injection nozzles are connected with the sump via a guide pipe.
The dish washing machine with the above-stated construction is operated as follows. After wash water is supplied into the washing tub, the wash water is introduced into the sump. By a pumping operation of the sump, the wash water flows to the injection nozzles through the guidance of a flow channel defined in the sump and a guide pipe connected with the flow channel, and is then injected to dishes at high pressure to wash food waste off the dishes. The wash water mixed with the food waste is reintroduced into the sump, and the above process is repeatedly carried out.
The filth chamber serves to collect the food waste mixed with the wash water. The filth chamber is connected to the flow channel. In an upper part of the filth chamber is mounted a mesh filter to separate the food waste from the wash water.
Specifically, when wash water and filth, including food waste, are introduced into the filth chamber, the wash water is reintroduced into the sump through the mesh filter mounted in the upper part of the filth chamber. However, the filth introduced into the filth chamber does not pass through the mesh filter but is left in the filth chamber. As the wash water repeatedly circulates, the filth continuously accumulates in the filth chamber.
When a drainage pump connected to the filth chamber is operated, the filth is discharged out of the dish washing machine.
However, when the mesh filter is clogged due to a rapid accumulation of the filth in the filth chamber, the wash water introduced into the filth chamber cannot flow out through the mesh filter. As a result, the water pressure in the filth chamber abruptly increases.
Consequently, the wash water is drained out of the dish washing machine due to the high water pressure although the drainage pump is not operated.